Grinding-mill.



B. M. ELY. :GRINDING MILL. APPLICATION FILED JULY 14. 1915- 1,220,154; Patented Mar. 20,1917.

UNITED STATES PATENT OFFICE.

BERNARD M. ELY, OF CINCINNATI, OHIO, ASSIGNOR COMPANY, OF CINCINNATI, OHIO, A

V 7 TO THE .ALVEY-FERG-U'SON CORPORATION OF OHIO.

GRIN DING-MILL.

Specification of Letters Patent.

Applicationfiled July 14, 1915. Serial N 0. 39,820.

being directed to a means which is particularly advantageous for use in securing the runner bur of a coffee m ll in proper correlation with its driving means: a particular purpose of the invention being to provide means for securing the runner bur on the driving shaft which means will be of such nature as to permit a certain limited amount of longitudinal movement order that no clamping effect will be obtained between the bur driving device and the bur, thus enabling the driving device to effect operation under normal conditions but to permit release of the driving device from the'bur readily under such abnormal condition as the presence between the burs of a foreign or hard body of a character liable to injure the burs if the grinding operation should continue.

The accompanying drawings illustrate the grinding portions of a coffee mill which embodies a constructlon and correlation of parts such as to carry into practice in a most satisfactory way, the foregoing purpose and other purposes which will hereinafterappear: and in said drawings whereln like characters of reference denote corresponding parts in the several views:

Figure 1 is a vertical median section through the grinding head of a mill embodying the improvements constituting the present invention. a I

Fig. 2 is an enlarged detail view, partly in elevation and partly in section showing the securing means for the male grinding element.

This invention, in respect to the applicationthereof herein illustrated, embodies an improvement on the bur securing means illustrated in the prior application of Frank 1 F. Wear and myself as joint inventors for improvements in coffee mills, Serial No. 872,186, filed November 14, 1914- As the improvements relate to the particular objects hereinbefore set forth, it is only made in the The head F also has tion gets between-the burs.

deemed necessary to illustrate and. describe Patented'Mar, 20,1917.

those parts which directly correlate with a such improvements and to this end many of the parts illustrated and described in the foregoing application have been omitted.

On a suitable base (not shown) is supported a motor ,B and the motor may be of any suitable construction or kind. This motor B is provided with a casing B from one end of whlch extends a sleeve or casing member 0,

a part of which forms the grinding chamher, the grinding being effected in that part of the sleeve which encircles the burs here.- inafter referred to. Mounted on the sleeve C is a head F which is connected to a suitable hopper through registering openings a sleeve and head through theseopenings the coffee berries flow from the hopper into the grinding chamber. The

grinding elementscomprise a male or runnerbur L and a female or stationary bur M. spouts O and 0. All Of these foregoing parts are or in practice be identical with those illustrated in the previously referred to application and accordingly'it is not deemed necessary more particularly to describe them in the present instance. v V

.The motor B has a shaft 10 which projects forward therefrom into the sleeve C and is arranged in the axial center of the latter. The runner bur L is mounted on the shaft 10. Suitable means are provided whereby injury to the teeth of either bur is prevent ed when. a nail, stone or other hard obstruc- Preferably the means referred to is of a nature such as that when a hard foreign substance gets between the burs, the motion of the runner bur is instantly stopped and said bur is caused to remain stationary until the obstruction is re- 7 moved.

The means herein exemplified for the purpose includes a back plate Q which is fixedly secured to the shaft 10, the runner bur being rotatable with relation to the shaft. The back plate is preferably provided with any suitable number of plungers 11 which are mounted in sockets 12 formed in the back plate and are pressed outward by springs 13 so that their heads normally protrude therefrom. The protruding portions'of the plungers are arranged to be seated in cavities 14: formed in the runner bur L and when they are thus seated the back plate Q communition of the runner cates motion of the shaft 10 to the runner bur. In a normal operation of the machine the back plate is connected to the runner bur in the manner set forth, but when a hard foreign substance gets between the burs it looks the runner bur and stationary bur together, the resistance afiorded by such substance to the runner bur, being suflicient to cause the springs 13 to yield, thus releasing the runner bur, the latter being now held against rotation by the hard foreign substance.

The runner bur has a long bearing portion 15 within which there is fitted an axial sleeve 16 having a frusto-conical exterior and a cylindrical interior. This sleeve is mounted on the reduced portion 17 of the shaft 10. The said shaft, including this reduced portion, extends approximately half-way of the length of the sleeve 16 and in the reduced portion 17 is formed a long screw-threaded socket 18 wherein is received a limit screw 19 by the adjustment of which the movement of the bur holding screw 20 may be limited in inward direction. This bur-holding screw 20 is provided with a head 21 which fits the shouldered mouth 22 of the sleeve 16.

By means of this peculiar arrangement the screw 19 may be adjusted so that when the screw 20 is screwed tightly against the screw 19 a slight clearance will be obtained between the sleeve 16 and head 21, the clearance being just sufficient to prevent that porbur which normally contacts with the back plate Q from gripping this back plate frictionally when the bur expands under the influence of the heat generated in grinding and thus preventing the proper operation of the releasing mechanism.

In the event that the back of the bur, where it contacts with the back plate Q, becomes worn or if the socket in the sleeve 16 or the head of the screw 20 becomes worn, the screw 20 may be removed and the screw 19 forced slightly farther into the threaded socket 18 and the screw 20 then reinserted until seated against the screw 19 thus compensating for any wear, the screw 20 at the same time preventing too much longitudinal play of the bur L.

It is to be understood that the stationary or female bur M is preferably mounted in the manner disclosed in the prior application hereinbefore referred to as illustrated at S. It is not deemed necessary to again repeat the specific details of the mounting of this bur as the same does not in any way affect the present improvements.

' Having now described my invention what I claim to be new and desire to secure by Letters Patent, is:

1. In a grinding mill, a driving shaft, a bur driving device fixed on the shaft, a bur loosely mounted on the shaft and releasably engaged by the driving device and means to hold the bur on the shaft arranged to regulate the pressure of the bur against the drivmg device 2. In a grinding mill, a driving shaft, a bur driving device fixed on the shaft, a bur loosely mounted on the shaft and releasably engaged by the driving device, means to hold the bur on the shaft arranged to regulate the pressure of the bur against the driving device, and a stop carried by and adjustable longitudinally of the shaft engaging the bur holding means to limit its movement in one direction.

3. In a grinding mill, a driving shaft, a back plate fixed on the shaft, a runner bur loosely mounted on the shaft, a slip clutch mechanism releasably connecting the back plate and bur, and means to hold the bur on the shaft arranged to regulate the pressure of the clutch mechanism.

l. In a grinding mill, a driving shaft, a back plate fixed on the shaft, a runner bur loosely mounted on the shaft, a slip clutch mechanism releasably connecting the back plate and bur, means to hold the bur on the shaft arranged to regulate the pressure of the clutch mechanism, and a shiftable stop carried by the shaft to limit movement of the bur holding means.

5. In a grinding mill, a driving shaft, a back plate fixed on the shaft, a runner bur loosely mounted, the back plate and runnerbur being provided with releasable clutch connections comprising coacting spring pressed plungers and sockets, and means to hold the bur on the shaft arranged to regulate the pressure of the clutch connections.

6. In a grinding mill, a driving shaft, a

back plate fixed on the shaft, a runner bur loosely mounted, the back plate and runner bur being provided with releasable clutch connections comprising co-acting spring pressed plungers and sockets, means to hold the bur on the shaft arranged to regulate the pressure of the clutch connections, and a shiftable stop carried by the shaft to limit movement of the bur holding means. 7. In a grinding mill, a driving shaft having an end provided with a threaded recess, a bur driving device fixed on the recessed end of the shaft, a runner bur loosely mounted on the recessed end of the shaft and releasably engaged by the driving device, a screw stop plug fitted within the recess and a screw arranged to hold the bur on the shaft fitted into the recess and butting against the stop plug.

8. In a grinding mill, a driving shaft provlded with a threaded recess, a back plate fixed on the threaded end of the shaft, a runner bur loosely mounted on the shaft, a slip clutch mechanism releasably conected to the within the recess on the shaft, and a screw arranged to hold the bur on the shaft fitted into the recess and butting against the stop plug.

9. In a grinding mill, a driving shaft, a runner bur loosely mounted upon said shaft, yieldable connections between the runner bur and the shaft, means to hold the bur on the shaft arranged to regulate the pressure of the yieldable connections and a shiftable stop for determining the limit of movement of the bur holding means.

10. In a grinding mill, a driving shaft, a runner bur loosely mounted upon said shaft, yieldable connections between the runner bur and the shaft, means to hold the bur on the shaft arranged to regulate the pressure of the yieldable connections'and a shiftable stop longitudinally adjustable With relation Copies of this patent may be obtained for five cents to the shaft for limiting the movement of the bur holding means. 7

11. In a grinding mill, a driving shaft, a runner bur loosely mounted upon said shaft, yieldable connections between the runner bur and the shaft, means to hold the bur on the shaft arranged to regulate the pressure of the yieldable connections and a shiftable stop carried by the shaft and longitudinally adjustable With relation thereto to limit the movement of the bur holding means.

In testimony whereof I aflix my signature in the presence of two Witnesses.

BERNARD M. ELY. Witnesses:

RUssELL L. Coon, HOWARD T. SALT.

each, by addressing the Commissioner of Patents,

Washington, D. G. 

